• Lower Yangzi macroregion 

• Indicator of retrospective fertility: women aged 30+ who have had 3+ children 

• Differentiate by Urban-Rural Continuum (URC, 8 classes) 

• Differentiate by Core-Periphery Zone

• Differentiate by cross-tabulated HRS zones

Examples drawn from G.W. Skinner, M. Henderson, and J. Yuan (2000).